Förenklad reologimätare för betong : Mätning av PWM-signal

Sammanfattning: Cement has a large climate footprint through the release of carbon dioxide in the manufacturing process. Rheometers, that measure the flow resistance in concrete, are available on the market today. They have very high accuracy but are also complex and expensive. There is a need for a simpler and cheaper measurement tool that complements existing, manual methods. Against this background, two research questions were created: • RQ1: How can a measuring paddle be rotated and the flow resistance be measured in a cost-effective way? • RQ2 - How can one build a machine without too expensive components with results similar to commercial rheometers? A prototype for measuring device, measuring electrical power, was designed and built based on the above research questions. The prototype was evaluated with two different liquids with known viscosity and two different concrete mixtures with different types of sand. The result is positive and shows a relation between flow resistance and used electrical power. However, additional tests and also calibration are needed.